Buffer means between link and shoe plate in a crawler type apparatus

ABSTRACT

Resilient buffer means connected between the links and shoe plate in crawler-type apparatus to absorb shock and vibration. Tractive force increasing members are mounted on the shoe plate adjacent the links and in contact therewith for increasing the tractive forces applied to the shoe plate from the links and for retaining the resilient buffer means and links against longitudinal movement relative to the shoe plate.

United States Patent Tomizawa MI Oct. 2, 1973 [54] BUFFER MEANS BETWEENLINK AND l,765,580 6/l930 Haggurl 305/46 H PLATE IN A CRAWLER TYPE2,211,897 8/1940 Johnston 305/54 APPARATUS [76] Inventor: KazuhiroTomizawa, 523 Kamagaya,

Kamagaya-cho, Higashikatsushika-gun, Chiba, Japan [22] Filed: May 25,1971 [21] Appl. No.: 146,723

[30] Foreign Application Priority Data July 29, i970 Japan 45/75446 [52]U.S. Cl. 305/46, 305/54 [51] int. Cl 862d 55/28 [58] Field of Search305/46, 54, 55

[56] References Cited UNITED STATES PATENTS 1,257,579 2/l9l8 Champlin305/46 Primary ExaminerRichard J. Johnson At!0rneyDavis, Hoxie,Faithfull & Hapgood [57] ABSTRACT Resilient buffer means connectedbetween the links and shoe plate in crawler-type apparatus to absorbshock and vibration. Tractive force increasing members are mounted onthe shoe plate adjacent the links and in contact therewith forincreasing the tractive forces applied to the shoe plate from the linksand for retaining the resilient buffer means and links againstlongitudinal movement relative to the shoe plate.

4 Claims, 4 Drawing Figures BUFFER MEANS BETWEEN LINK AND SHOE PLATE INA CRAWLER-TYPE APPARATUS The present invention relates to heavyconstruction machines. More specifically, the present invention relatesto buffer means arranged between the links and shoe plate in acrawler-type apparatus, e.g., bulldozers, shoveldozers and the like.

With the increase in construction work it is desirable to reduce thedown-time of construction machines and at the same time to increase thequantity of work per unit time by increasing the operatingspeed ofconstruction machines.

Heavy construction machines such as bulldozers, shoveldozers and thelike used at present in working the earth employ a crawler tractionsystem requiring low ground contact pressure to supply mobility'to'themachine. In such construction machines, a shoe plate is bolted directlyto the rear of two links. In operation,

, and particularly at the higher speeds desired to increase the quantityof work, the shoe plate is subjected to shock and vibration caused byobstacles, e.g., rocks and the like, and the irregular contour of theearth. Such shock accelerates abrasion, breakage and fatigue in themachine components resulting in shortened machine life.

It is the principal object of the present invention to provideconstruction machines having means capable of increasing work output.

It is a further object of the present invention to allow constructionmachines to be operated for long periods at high speed.

It is a further object of the present invention to reduce the amount ofabrasion, breakage and fatigue occurring in construction machines,thereby prolonging machine life.

It is a further object of the present invention to provide means forincreasing the tractive forces applied to the shoe plate from the links.

It is still a further object of the present invention to provide meansfor reducing the operating noise level of the machine and the vibrationand shock during operation to create a more pleasant environment for theoperator and to aid in preventing accidents resulting from operatorfatigue.

Briefly, buffer pads are provided between each link and the shoe plateof a crawler-type apparatus. Two sets of paired link guides or ribs arearranged on the upper surface of the shoe plate, forming buffer padreceiving channels. A link is positioned between each set of ribs andconnected to the shoe plate through a resilient pad, whereby the shockinflicted upon the shoe plate may be absorbed by the elastic deformationof the resilient pad; and abrasion of the link and rotary wheels, anddamage to the bearings is prevented by reducing the intensity of themechanical shock between each link and the lower rotary wheel. Further,a set of ribs is arranged adjacent each link and in contact therewithfor increasing the tractive force applied to the shoe plate from thelinks.

Other objects, aspects and advantages of the present invention, as wellas the objects previously mentioned, will be more fully understood whenthe detailed description is considered in conjunction with the drawings, as follows:

. FIG. 1 is a perspective view of a conventional link and shoe platestructure for use in a crawler-type apparatus;

FIG. 2 is a perspective view of the assembled buffer means according tothe present invention;

FIG. 3' is an exploded perspective view of the apparatus of FIG. 2 withone link omitted for ease of description;

FIG. 4 is a cross-sectional view taken along line IVIV in FIG. 3.

Referring to FIG. 1, a conventional shoe plate 1 is shown'connecteddirectly to a pair of links 2 by means of nuts and bolts 3. In contrastto the conventional apparatus as shown in FIG. 1, the buffer meansaccording to the present invention is shown in FIGS. 2 through 4.

Referring particularly to FIG. 3, a shoe plate 5 is shown having twopairs of rigid, spaced, substantially parallel link guides or ribs 6 and6a fixedly arranged thereon. Each pair of link guides or ribs 6 and 6ahas semi-circular notches 7 and 7a, respectively, symmetrically formedin the front and rear thereof and arranged for axial alignment with boltapertures 8 and 8a, respectively, formed in the shoe plate 5. Each pairof ribs "6 and 6a defines a resilient-memher-receiving channel forreceiving a resilient member or pad 10 and maintaining the longitudinalposition of the resilient pad 10 relative to the shoe plate 5. Theresilient memberslO each include semi-circular notches 11 and 11acapable of mating with notches 7 and 7a, respectively, forming bushingholes axially aligned with apertures 8 and 8a, respectively.

Further, each resilient member 10 includes a locking protrusion or key10a adapted to fit within the portion of the channel 5a, formed in theupper surface of the shoe plate 5, that is within each receiving channelformed by the pair of ribs 6 and 6a, to lock. the resilient member 10against substantial transverse movement. The resilient members or pads10 may be formed from a high polymer compound such as sythetic rubber,polyurethane and the like.

Links 13 are mechanically coupled to the shoe plate 5 and providemechanical coupling of the tractive forces thereto. The links 13 includeflanges 14 and 15 integrally formed therewith and arranged between theribs 6 and 6a, in contact therewith. The flanges 14 and 15 includenotches 14a and 15a capable of mating with notches 7 and 7a of the ribs6 and 6a, respectively, forming bushing holes axially aligned withapertures 8 and 8a, respectively.

Although, as shown in FIGS. 2 and 3, the notches7 and 7a formed in theribs 6 and 6a cause portions of the ribs 6 and 6a circumjacent thenotches 7 and 7a to extend outwardly in a semi-circular configuration,it is to be understood that the ribs 6 and 6a may be made wider toeliminate the outward projections- The ribs 6 and 60 may also includereinforcing ridges l7 and 17a connecting the ribs 6 and 6a to the shoeplate 5 for further strengthening the ribs 6 and 6a.

Cut-out sections 18 are formed at the rear edge of the shoe plate 5,generally extending approximately the width of the spaced ribs 6 and 6a,for allowing the toothed periphery of the sprocket (not shown) to passtherethrough during operation of the crawler-type apparatus.

When assembling the apparatus according to the present invention, asshown in FIGS. 2 through 4, the resilient members or pads 10 are fittedwithin the receiving channels formed by the two sets of paired ribs 6and 60, respectively, and placed in contact with the ribs 6 and 6a andthe upper surface of the shoe plate 5. Notches 11 and 11a are mated withnotches 7 and 70, respectively, axially aligned with bolt apertures 8and 8a, respectively. Links 13 are placed upon the resilient pads withthe notches 14a and a mated with notches 7 and 7a, respectively, andthereby forming bushing holes adapted to receive locking bushings 23.

Bolts are inserted through the bolt holes 8 and 9 from the lower surfaceof the shoe plate 5, as shown in FIG. 3, and locking bushings 23 arepositioned circumferentially about the threaded portion of the bolts 20in the bushing holes, as shown in FIG. '4. Nuts are mated with the boltthreads to provide a compressive force which acts on the peripheralflanges 24 of the locking bushings 23 to hold the resilient members 10and links 13 in position relative to the shoe plate 5.

The links 13 are held by the compressive action of the bushing flanges24 on the rib surfaces circumjacent the notches 7 and 7a and on theflange surfaces circumjacent the notches 14a and 15a of the links 13,the resilient pads 10 are thereby compressively held beneath the flanges14 and 15 of the links 13.

The thickness of the ribs 6 and 6a relative to the flanges l4 and 15 andresilient members 10 is such that the locking bushings 23 compressivelyretain the resilicnt members 10 with a compressive force below theaverageload and within the elastic limit of the resilient members 10 toprovide a buffer action. The elasticity and hardness of the resilientmembers 10 may be advantageously varied in response to machine andground hardness.

Since the flanges l4 and [5 of the links 13 are pressed downwardly, witha force within the elastic limit of the resilient members 10, toward theshoe plate 5 by flanges 24 of the locking bushings 23, and the lockingbushings 23 are connected with the semicircular notches 14a and 15a ofthe flanges l4 and 15 and the semicircular notches 7 and 7a of the ribs6 and 6a, the tractive force imparted to the links 13 is transmitted tothe shoe plate 5 through the locking bushings 23. Any tractive forceacting on the links 13 is thereby transmitted to the shoe plate 5' bythe ribs 6 and 6a, providing a tractive force that is more than twice asgreat as that of the conventional apparatus shown in FIG. 1, where theshoe plate 1 is connected directly to the link 2 through bolts and nuts3.

When a crawler-type apparatus according to the present invention isoperating, any shock inflicted upon the shoe plate 5 is absorbed by thevertical deformation of the resilient pads 10, and the shock between thelinks 13 and lower rotary wheels (not shownlis substantially reduced.During deformation, the resilient pads 10 may protrude, slightly beyondthe transversely extending ribs 6 and 60; however, since the resilientpads 10 are held in position by the locking bushings 23 withinsemi-circular notches ll and Ila, and the locking protrusions 10a arepositioned within the channel 5a, the resilient pads 10 are preventedfrom working free during operation.

It should be understood by those skilled in the art that variousmodifications may be made in the specific structure employed in thebuffer means according to the present invention without departing fromthe spirit or scope thereof, as described in the specification anddefined in the appended claims.

What is claimed:

1. Buffer apparatus for use with crawler-type apparatus, comprising:

a shoe plate,

a pair of links mechanically coupled to said shoe plate to providecoupling of the tractive forces from the crawler-type apparatus to saidshoe plate,

a pair of resilient deformable buffer pads, one of said pair of padspositioned beneath one of said links to absorb shock and vibrationsencounted by said shoe plate, said resilient deformable buffer padsextending in the direction in which said shoe plate is moved by thecrawler-type apparatus,

two pair of tractive force increasing ribs mounted on said shoe plateand extending in the direction in which said shoe plate is moved by thecrawler-type apparatus, each pair of said ribs being arranged to receiveone of said resilient pads and one of said links to maintain thelongitudinal position of said pads and said links on said shoe plate andincrease the tractive force applied to said shoe plate from said pair oflinks, and

means for compressively coupling said pair of links to said shoe platethrough said pair of resilient buffer pads.

2. Buffer apparatus as recited in claim 1, wherein:

said shoe plate includes a channel between said ribs of each pair ofribs,

each of said resilient buffer pads includes a depending protrusionreceived by said channels for locking said resilient buffer pads againsttransverse movement on said shoe plate to maintain the relative positionbetween said shoe plate and said resilient buffer pads.

3. Buffer apparatus as recited in claim 1, wherein:

each of said tractive force increasing ribs includes reinforcing meansconnecting said ribs and said shoe plate.

4. Buffer apparatus for use with crawler-type apparatus, comprising:

a shoe plate,

link means mechanically coupled to said shoe plate to provide couplingof the tractive forces thereto,

resilient deformable buffer means arranged between said link means andsaid shoe plate to absorb shock and vibrations encounted by said shoeplate,

tractive force increasing members mounted on said shoe plate adjacentsaid link means and in contact therewith for increasing the tractiveforce applied to said shoe plate from said link means and for retainingsaid resilient buffer means and said link means against longitudinalmovement relative to said shoe plate, said tractive force increasingmembers being transversely extending positioning ribs which are coupledto said shoe plate for maintaining the longitudinal position of saidresilient buffer means and said link means relative to said shoe plate,said ribs are formed on said shoe plate extending transverselytherealong in a spaced, substantially parallel arrangement, defining aplurality of separate buffer receiving channels, each of said ribshaving at least one notch arranged therein,

said shoe plate includes apertures arranged therein axially aligned wtihsaid rib notches,

bushing holes, each of said locking bushings having a peripheral flangepositioned circumjacent said bushing holes in contact with said linkflange and said adjacent rib, and

means for compressively coupling said link means to said shoe platethrough said resilient buffer means, said compressive coupling meansincluding bolt means arranged within said shoe plate apertures andextending axially through said locking bushings for exerting compressiveholding forces on said link flanges and said ribs through saidperipheral flange.

1. Buffer apparatus for use with crawler-type apparatus, comprising: ashoe plate, a pair of links mechanically coupled to said shoe plate toprovide coupling of the tractive forces from the crawler-type apparatusto said shoe plate, a pair of resilient deformable buffer pads, one ofsaid pair of pads positioned beneath one of said links to absorb shockand vibrations encounted by said shoe plate, said resilient deformablebuffer pads extending in the direction in which said shoe plate is movedby the crawler-type apparatus, two pair of tractive force increasingribs mounted on said shoe plate and extending in the direction in whichsaid shoe plate is moved by the crawler-type apparatus, each pair ofsaid ribs being arranged to receive one of said resilient pads and oneof said links to maintain the longitudinal position of said pads andsaId links on said shoe plate and increase the tractive force applied tosaid shoe plate from said pair of links, and means for compressivelycoupling said pair of links to said shoe plate through said pair ofresilient buffer pads.
 2. Buffer apparatus as recited in claim 1,wherein: said shoe plate includes a channel between said ribs of eachpair of ribs, each of said resilient buffer pads includes a dependingprotrusion received by said channels for locking said resilient bufferpads against transverse movement on said shoe plate to maintain therelative position between said shoe plate and said resilient bufferpads.
 3. Buffer apparatus as recited in claim 1, wherein: each of saidtractive force increasing ribs includes reinforcing means connectingsaid ribs and said shoe plate.
 4. Buffer apparatus for use withcrawler-type apparatus, comprising: a shoe plate, link meansmechanically coupled to said shoe plate to provide coupling of thetractive forces thereto, resilient deformable buffer means arrangedbetween said link means and said shoe plate to absorb shock andvibrations encounted by said shoe plate, tractive force increasingmembers mounted on said shoe plate adjacent said link means and incontact therewith for increasing the tractive force applied to said shoeplate from said link means and for retaining said resilient buffer meansand said link means against longitudinal movement relative to said shoeplate, said tractive force increasing members being transverselyextending positioning ribs which are coupled to said shoe plate formaintaining the longitudinal position of said resilient buffer means andsaid link means relative to said shoe plate, said ribs are formed onsaid shoe plate extending transversely therealong in a spaced,substantially parallel arrangement, defining a plurality of separatebuffer receiving channels, each of said ribs having at least one notcharranged therein, said shoe plate includes apertures arranged thereinaxially aligned wtih said rib notches, said resilient buffer meansincludes a plurality of resilient buffer pads having mating notchesarranged therein for mating with said rib notches when said resilientbuffer pads are positioned within said buffer receiving channels, saidlink means includes a plurality of links having flanges with matingnotches arranged therein, said links being positioned on said resilientbuffer pads for mating said flange notches with said rib notches to formbushing holes in communication with said apertures, locking bushingsadapted for insertion within said bushing holes, each of said lockingbushings having a peripheral flange positioned circumjacent said bushingholes in contact with said link flange and said adjacent rib, and meansfor compressively coupling said link means to said shoe plate throughsaid resilient buffer means, said compressive coupling means includingbolt means arranged within said shoe plate apertures and extendingaxially through said locking bushings for exerting compressive holdingforces on said link flanges and said ribs through said peripheralflange.